Asymmetry in force production between unilateral and bilateral standing broad jumps in young senior amateur basketball players

Abstract

The main aim of this study was to assess the between-session reliability of performance and asymmetry variables between unilateral and bilateral standing broad jumps (SBJ). Twenty-four amateur basketball players completed two identical sessions which consisted of four unilateral SBJs (two with each leg) and two bilateral SBJs. Mean and peak values of force, velocity and power, and impulse were obtained separately for each leg using a dual force platform. Inter-limb asymmetries were computed using the standard percentage difference for the unilateral SBJ, and the bilateral asymmetry index-1 for the bilateral SBJ. All performance variables generally presented an acceptable absolute reliability for both SBJs with some exceptions for mean force, mean power, and peak power obtained with both legs. Asymmetry variables always showed unacceptable reliability and slight to fair levels of agreement in their direction except for unilateral SBJ peak velocity and bilateral SBJ peak power that showed moderate agreement for both SBJs. These results highlight that single-leg performance variables can be generally obtained with acceptable reliability regardless of the SBJ variant, but the reliability of the inter-limb asymmetries in the conditions examined in the present study is unacceptable to track individual changes in ground reaction force production.